Fuel oil burner



Feb. 18 1941. FARRELL 2,231,893

FUEL OIL BURNER Filed Aug. 5, 1938 2 Sheets-Sheet 1 3 Fig 7 1 l/ 1 1 34 1 g4 INVENTOR.

JIZZhrreZL,

BY 96,338 97.0%TT0RNE? Feb. 18, 1941.

J. E. FARRELL FUEL OIL BURNER Filed Aug. 5, 1938 2 Sheets-Sheet 2 1N VEN TOR.

A TTORN Y JECZ Zzrre Patented Feb. 18, 1941 UNITED STATES FUEL on. BURNER Joseph E. Farrell, Toms River, N. .L, assignor to National Engineering Foundation, Inc., Washington, D. 0., a corporation of Delaware Application August 5, 1938, Serial No. 223,308

4 Claims.

This invention relates to fuel oil burners, and more particularly to novel means for converting the fuel oil into a gas before it is burned, thereby obtaining efllcient combustion which produces intense heat, without the formation of carbon, and at less cost than burning the raw fuel.

One of the objects of the invention is .to provide means for shielding the gas outlets of the generating head in such a way that gas pressure may be built up in the generating head progressively without interference from the' air blast, thereby eliminating the use of pumps or other accessories heretofore regarded as necessary to force gas into an energized air stream. That is to say, the present invention leads the gasifled fuel into the energized air of a mixing chamber from behind a baille or deflector, and because of the tendency of the air passing over the bafhe to create a vacuum at the leading edge thereof, the gas is pulled into the air stream regard-' less ofitsown pressure.

Another and important object of theinvention is to provide a novel arrangement of parts which will assist in preventing the formation of-carbon in the gas generating unit before the fuelv oil is completely gasified. In order to convert the fuel oil into gas, "it is, of course, necessary to subject the same to a degree of heatwhich' causes the oil to boil, and to avoid this boiling at any point prior to its admission to the gas generating head of the unit, on which there is concentrated a degree of heat sufllciently high to effect gasiflcation completely and instantaneously, suitable means is provided for keeping the pipe for supplying fuel oil to the head relatively cool.

- A further object is to provide novel means for starting the operation of the burner which-causes the spark ignited initial supply of raw fuel to be projected by air jets in. torch formv against the underside of the gas generating head. These jets are initially intensified by an i air supply bypassed into the burner or generator unit from the mixing chamber, and deflected downwardly toward the base of the Jets by a novel cowl ring. Later on in the operation of the 'unit, afterthe gas generation gets under way, the mixture 'of air and gas from the mixing chamber is bypassed into the unit, and the cowl ring directs the mixture into the path of the air jets so that this flaming mixture is also projected toward the gas generating head.

A general object of theinvention is to provide a fuel oil gas generating unit which may; be automatically started in operation by an .electrical spark discharge, and to which the fuel is deflector plate for directing the flame issuing 2 modifl'edform of nozzle.

'sponding parts through the several flguresof the supplied by conventional automatically controlled devices thus rendering a burner of this type particularly adapted to any of the usual domestic uses such as the heating of household furnaces, stoves or the like, in a simple and practical man- 5 ner.

With the above and other objects in view which will more readily appear as the nature of themvention is better understood, the same consists in the novel construction, combination and ar- 10 rangement of parts hereinafter more fully described, illustrated and claimed- A preferred and practical embodiment of the invention is shown in the accompanying drawings, in which: I 15 Figure 1 is a vertical sectional view of the improved burner.v

Figure 2 is a detail vertical sectional view of 'a portion of the generator unit taken at an angle of from Figure 1.

Figure 3 is a horizontal cross section taken on the line 3-: of Figure 1.

Figure 4 is a detail sectional view of a type of from the burner head laterally.

Figure 5 is a detail sectional view of a modifled form of flame deflectorintended to concentrate the flame at a particular point.

Figure 6 is a detail sectional view showing how the gas outlet openings of the burner head may '30 be. capped to convey the gas to a remote point of use.

Figure 7 is a detail sectional view showing a further modified arrangement for sealing the gas outlet openings of the burner head to permit the 35 gas generated by the unit to be also carried to a remote point of use:

' Figure 8 is a detail vertical sectional view showing a modification using a guide or deflecting collar in conjunction with the cowl.-

Figure 9' a detail sectional view showing a Similar reference characters designate corredrawings. p

According to the'embodiment' shown inthe drawings, the invention includes in its-,organization a casing designated generally as A, air supplying means B, and a gas generating unit C connected with a main source of fuelsupply through l the valve D. An auxiliary source of fuel supply is provided through valve D for supplying fuel to the initiator receptacle or burner pot C as will later appear.

The casing A may be of any desired cross-sectional shape although it preferably partakes of the nature of a bowl and in the example shown is of substantially frusto-conical formation. The upper edge of the casing may be provided with an outwardly extending hearth flange I and a seat 2 for receiving a burner plate designated generally as E. This plate may be of any suitable formation and preferably has a central opening 8, and the outwardly located Jets 4 formed in thickened flange or grid portions which give ample length or depth to the jets to'insure flame propagation at the outside face of the plate and prevent backfire. The burner head E constitutes ineflect acoverforihecasingaandeooperates therewith to provide a mixing chamber M. The lower portion of the casing is formed with an upstanding collar A surrounding an opening which receives one arm of an air supply conduit preferably capable of circumferential adjustment thereabout.

The gas generator unit C includes a hollow gas generating head 8 comprising a cover 8 and a base l8 suitably interengaged to provide a gas generating compartment II. The base I! has centrally fltted thereto a fuel oil supply pipe l2 which passes through the entire'unit and thence downwardly through the mixing chamber and one arm of the air supply conduit I where its lower end I8 is connected by a coupling l4 with a lateral supply pipe I! leading to the main fuel supplyvalve D. This valve is in turn connected with a supply line [6 having therein a constant level valve (not shown) of any conventional type to insure the supply of fuel oil to the pipe l2 and burner head 8. This constant level valve in the line determines the height of the fuel in the supply pipe and that level is so adjusted that expansion of the liquid fuel under heat forces an overflow in the base II of the generator head and which overflow is immediately converted into dry gas, and which, as will presently appear, escapes nited by contact with the flame of the initiator burner which mushrooms out from under the the generating head 8 is supported by the pipe 12 above the opening 8 in the burner head, and

the inner end of the pipe l2 projects above the base of the generating head l8 as'indicated at l2a. The base I8 also carries therewith a plurality of downwardly extending gas tubes 18 whose upper ends [8a are disposed above the inner face of the base ill thereby to provide means for temporarily holding or trappinga small quantity of oil in the head 8 to be subjected to flame-issuing through the central opening 8 of the burner head when the humer is started as will later appear more in detail. The gas passage means I! may be of any duct form singular or plural, or be composed of tubes in the construction shown is tubular, and four in number. The opening 8 of the burner plate is preferably constricted by a removable cowl 28 which is preferably of annular dome-like formation and has its outer edge 2| resting on a suitable shoulder in the burner plate while its cross sectional shape is such as to provide a substantially vertical downwardly directed inner wall 22 which cooperates with the outer wall thereof to provide an arched chamber 28 lying substantially above the opening 8 in the burner plate.

The gas generating unit further includes flame initiating means in the form of a receptacle C [for receiving initial supply of fuel to effect the starting of the burner. Said receptacle may be conveniently termed a burner pot and includes a bottom wall 24,- through which the outlet or discharge ends lib of the gas return tubes l8 project, and an upstanding side wall 25-, the latter provided with a plurality of suitably disposed by-pass openings 28 which establish communication between the mixing chamber M and the generating unit. That is to say, the openings 28 are directed upwardly toward the inner face of the wall 22 of the cowl 28 so that air or the mixture of air and gas from the chamber M will be discharged upwardly into the annular chamber 28 of the cowl and be mushroomed down into the bottom of the receptacle C. The bottom wall 24 of the initiator pot also has fltted thereto a well 21 which surrounds and insulates a part of the fuel oil supply pipe 12 from direct heat of the flame propagated 'in the receptacle. The bottom wall 28 of the well is provided with a threaded opening for engaging with threads 28 formed on the pipe l2. These threadsare of suflicient extent to also receive the central threaded opening of a shield or bailie member 88 which may be locked in position by the nut 8| also engaging the threads 28. The baiiie 88 is thus held in spaced relation to the bottom wall 24 of the burner pot and its peripheral portion is flared upwardly so that its outer edge will deflect the air blast issuing from the air supply duct 5 outwardly toward the openings 4 in the burner plate and at the same time tend to produce a vacuum in the space between the baflle and the bottom 24 of the burner pot, which vacuum will have a tendency to draw or suck gas from the outlet generator head. At this point it may also be ends l8b of the gas return tubes l8 into the air stream which eddies in the mixing chamber to mix with the gas.

The bottom wall 24 of the burner pot is also pierced by a plurality of air nozzles 82 whose lower ends 88 are of substantially bell mouth formation. Said lower ends 88 also project through the baflie 88 to be exposed to the air blast while the upper ends of the nozzles, provided with a bore of less diameter than the bell ends 88, form a plurality of air jets 84 directed upwardly toward the bottom of the generating head 8.

Starting fuel is supplied to the initiating burner pot or receptacle by pipe 85 leading through the side wall 25 thereof and having its lower end 38 communicating with the magnetic valve D. This valve is automatically controlled to supply a quantity of starting fuel when demand is made on the burner, by conventional thermostatic devices for controlling the same, and is synchronized with an electrical igniting device 81 of any conventionalspark producing type. This device includes a porcelain casing tiple.

The operation of the device is substantially as follows:

Fuel oil is supplied to the head 8 of thegas generating unit C through the supply connec tlons i2-l6, inclusive, and-the valve D, said connections including a constant level valve which maintains oil in the head 8 in sufflcient quantity to surround the upper ends I26! and Na of the fuel supply and gas tubes I2 and I9 respectively.

When the device is to be started the thermostatic control means (which may be of any conventional type) closes the circuit to the magnetic starting valve D which feeds a quantity of ofl to the burner. pot where it is held between the bottom wall 24 and side wall 25 thereof to be ignited by the vapors arising therefrom under pressure of down draft from the passages 26 and cowl 23 when said vapors are ignited by the electrical spark discharge device 31. The blower 6 starts to function simultaneously with the supply of fuel to the burner pot and the operation of the spark device. I into themixing chamber M strikes the shield or baiile 30 and caroms off toward thei'et openings 4 in the burner plate E. However, a certain amount ofthe air issuing from the duct 5 enters the bell ends 33 of the nozzles 32 so that air issues from the jets 34 and in cooperation with the down draft from the cowl induces a partial vacuum in the receptacle or burner pot and pulls or pushes the flame of the ignited oil upwardly to produce a plurality of torches directed upwardly within the space formed by the wall 22 6 of the cowl ring 20 against the base I of the burner head. The intense heat formed by the torches propagated and projected from the upper ends 34 of the nozzles 32 immediately starts the gasification of the quantity of fuel trapped in the base of the burner head. The gas thus formed in the burner head escapes downwardly there! from through the gas return means into the space between the bottom wall 24 of the, recep-' tacle and the upper face of the baffle, the latter protecting the same from the directjorce of the air blast issuing from the conduit 5. The vacuum caused by air passing off edge 3 I of the baiile will pull the gas into the mixing chamber M "and cause a gaseous mixture to be' formed which gaseous mixture may follow two courses, namely, upwardly through the heating jets 4 of the burner head E and also through theby-pass openings 28 in the side wall 25 of the burner pot. The flame forced upwardly by the nozzles 32 is not only, concentrated under the burner head 28 but alsomushrooms outwardly to ignite the gaseous mixture issuing from theheating jets 4 of the-burner plate. Thus, the burner is placed in full oper- ,ation.

After a short period of operation the magnetic starting valve. D closes and the igniting device 31 ceases to operate and such starting fuel ,as may remain in the burner pot is consumed.

Meanwhile, however, it will be understood that the gas generating head is in full operation, and

that the fuel which is converted into gas in said initial or starting flame ceases, the gas generating The air blast issuing from the conduit 5 I head furnishes sufilcient fuel to provide sustained combustion, not only at the Jets 4 of the burner plate, but also in the gas generating unit due to the fact "that'part of the gaseous mixture formed in the mixing chamber M is supplied to the gas 6 generating unit through the medium of the bywas openings, 28 which, as previously-indicated, are disposed toward the inner face of the wall 22 of the cowl; The gaseous mixture issuing from the jets 28 becomes ignited and the flame propl0 air Jets 34, through the opening provided by the 1 wall 22 of thecowl, to be directed and concentrated on the base [0 -of the generating head, thus sustaining continued conversion of the liquid fuel supplied to the head 8 into gas. I

a The provision of the well 21 surrounding'the 20 medial portion of the fuel supply pipe 12 has the important function of keeping the pipe relatively cool, that is, .cooier than the gas return pipes which surround the same to avoid the heating of the fuel to the boiling point before it reaches the 25 gas generating head 8. In other words, the mef dial portion of the oil supply tube I2 is shielded from the flame in the burner pot due to the air space provided by the well 21, and the vacuum formed above it by the rising heat and further- 30 mixing chamber relatively cool. 35

In practice it has been found that the well 21 and the bafllej plate 30 perform extremely practical functions which insure the successful operation of the burner.

f -That is to say, the well 21 surrounding the fuel 0 pipe i2 extends downwardly to the point where cooling air from the energizing means terminates the boiling possibility of the fuel content of the pipe. Rising heat from the initial fire in the receptacleor initiator burner pot. C and. updraft 5 through the cowl opening creates a vacuum in the well and prevents conduction of heat down the fuel pipe; and this vacuum is maintained at increased intensity when the primary fire comes into being. Actual tests have proved that when 50 the well is made deep enough and its wall highenough to cover. a pre-determined boiling range, the 011 does not boll until it actually reaches the,

generator head 8 where it is broken down into gas so quickly that whatever time element exists 55 between boiling and gasification is so relatively insignificant that no deposit of carbon or other 1 chemical components-of unburnable character appear after many hours of operation.

'The bafiie or shield 30 not only prevents air so from-theblower, issuing from the conduit 5, entering the lower ends I9b ofthe tubes I8 to avoid building up counter, pressure in the gas generating head, but at the same time, air rush ing past the edge 3| of the baflle tends to produce 05 a vacuum at the upper side of the baiile thereby effectively 'entraining low pressure gas into the higher pressure air'stream and thus energization of the-mixture is accomplished without the use of compressor means. l'his new form of energi- 7o zation 'assures efflcient'gas distribution to the burner vents 'or'iets, or if they are closed, the

gas can be piped from the'mixing chamber to any other gas fired apparatus placed at a point relatively remote from the unit itself."

Figures illustrates-the use of a flame guiding plate 40 in conjunction with the primary burner plate E to direct the flame outwanilyn -fi'for'example, against the side walls of a domestic boiler or the like. The deflector 40 may bemade in the form of a continuous ring or insections, prefer-1 ably. the latter, and the lower edge 4i thereof may be adaptedto fit in the groove 42 of the burner plate lying at one side of the jet openings 4.

Figure 5 illustrates further means for directing or concentrating the flame at a particularpoint. In this form of construction the burner plate E is provided with jet. openings 4a which are enclosed by the upstanding sleeve elements and 44. The outer sleeve 43 may be engaged with the outer wall of the rib in which the openings 4a are located while the. inner sleeve 44 may rest against the upstanding collar a on the removable cowl 20.-

Figure 6 illustrates the application of a ringlike hood 45 to the burner plate E shown in Figure 1 to cover the jet openings 4 thereof and thus collect all the gas issuing from the jets 4 so that it may be taken out through the valve 46 to be used at a remote point. When the hood 45 is applied as indicated in this figure it will, of course, be understood that the gas generating unit C functions in the manner heretofore described to produce the gas.

A further modification for conducting gas to a remote point of use is illustrated in Figure 'I from which it will be noted that'the jets 4 of the burner plate E may be capped by a plate 46 so as to prevent gas issuing from any of the jets. In this case the gaseous mixture is led oil from the mixin chamber I by a pipe 41 which is tapped into the wall of the casing A. a

The foregoing modifications are simply intended to be illustrative of the range of application of the invention to various types of burners and it will, of course, be understood that other forms of construction for attaining these ends may be resorted to within the scope of the invention.

Figure 8 of the drawings illustrates the use of a ring or guide collar 20a within the receptacle and extending into the arched chamber 23 formed by the removable cowl 20. That is to say, the annular ring or collar 200. may be inserted into the upper end of the receptacle C and have its upper portion extend into the chamber 23 so that initial air, and later a mixture of air and gas, discharging from passages- 28 into the chamber 23 will be directed upwardly and thence downwardly as indicated by the arrows in Figure 8. According to the illustration in Figure 1 the by-pass openings 26 being obliquely disposed, discharge toward the down-turnedwall 22 of the cowl so that air or gas issuing therefrom first strikes the wall 22 and is then directed substantially clockwise and downwardly toward the bottom wall- 24 of the receptacle. By the modi- 1 fication shown in Figure 8, however, the air or gas issuing from the by-pass openings 26 is directed upwardly and substantially along the outer wall of the cowl 20 before it is turned in a substantially counter-clockwise directionand thence downwardly into the receptacle C. Under some conditions of use the modified arrangement effects a more complete scavengingpf the receptacle C or in other words more quickly burns out the charge of initial fuel fed to the receptacle C due to the fact that the air, or the gaseous mixture is mushroomed directly and downwardly on to the floor or bottom wall 24 of the receptacle.

Figure 9 illustrates .a modified form of nozzle which hasthe same general purpose in-view as the modification shownin Figure 8, to direct initial air, or subsequently gaseous mixture downwardly toward the bottom of the receptacle or burner pot C. The nozzle 32a is fitted into the bottom 24 of the receptacle 0' andv through the deflector 3|! in the same way as the nozzles 32 are in Figure 1. H However, the upper ends of the nozzles ua are provided with hoods 340' while the side walls of the nome itself are provided with t lateral discharge port! 34b. Therefore, air, will pass through the nozzles 12 and discharge within the hood 34 and .thus be directed downwardly toward thebottomwall 24 of the burner pot.,

Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and itwill, of course, be understood that changes in the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention and scope of the appended claims.

I claim:

1. A fuel burner for converting liquid fuel into gas including, a gas generating unit, said unit having a receptacle for receiving an initial quantity of fuel to start the burner, igniting means therefor, said receptacle including a bottom wall and side walls, the latter having a plurality of upwardly directed by-pass openings, a ring-like cowl member having an annular'chamber for receiving discharge from said by-pass openings, 9. gas generating head mounted above said cowl member, aliquid fuel supply pipe connected with said gas generating head, a plurality of gas tubes connected with said gas generating head and extending downwardly through said receptacle and opening at the underside thereof, a baiiie carried by the receptacle and spaced from the lower wall thereof, and a plurality of nozzles carried by the bottom wall of the receptacle, said nozzles having their upper ends discharging toward said gas generating head and having their lower ends opening through said baiile.

2. A fuel burner for converting liquid fuel into gas including, a casing, a foraminous burner plate having a central opening and cooperating with the casing to provide .a mixing chamber, air supply means for said mixing chamber, a gas generating unit arranged at said central opening, said gas generating unit including a hollow gas generating head having .a liquid fuel supplyconnection, and gas outlet tubes, 9. cowl of'transversely arched cross-section having a central opening surrounding said tubes and also having its outer edge resting on said burner plate, said opening in the cowlbeing located beneath the hollow generating head and the outer edge of the cowl overhanging the central opening in the burner plate; and means for initiating the con-. version of liquid fuel in generating head into gas,

means for shielding the open ends of the gas tubes from the air blast.

3. A fuel burner for converting liquid fuel into gas including a casing having a burner plate provided with jet openings and'a central opening, said plate cooperating with the casing to form a mixing chamber, air supply means for said mixing chamber; a gas generating head disposed above the central opening of the burner plate, said gas generating head having tubes extending into the mixing chamber, means in the mixing chamber for shielding said tubes from the direct force of said air supply; and means for preliminarily and subsequently'heating said gas generating head, said means comprising a receptacle located below the central opening of said burner plate for receiving starting fuel, means for igniting said starting fuel, nozzles for supplying air to said receptacle to cause the flame propagated from the initial fuel supp y to be projected upwardly in the form of torches toward the gas generating head, and means for supplying sustained heat to the gas generating head after the initial supply is exhausted, said means comprising a cowl having an arched wall overhanging the central opening of the burner plate, and a plurality of by-pass openings in the side wall of the receptacle for establishing communication between the mixing chamber and the cowl.

4. A fuel burner for converting low grade liquid fuel oil into superheated dry gas, comprising, a casing, a burner plate having a "central opening and a plurality of elongated gaseous mixture openings whichlimit combustion to their discharge ends, said latter openings being located between said central opening and the marginal edge of the plate which rests on the casing to provide a mixing chamber, and a combined dry gas generating and liquid fuel starting unit disposed at the location of said central opening, said unit including a starting liquid fuel receptacle provided with electric ignition means, a dry gas generating head above the receptacle and communicating with a source of fuel supply, dry gas tubes connected with the generatinghead and extending through the receptacle into the mixing chamber, a baflie plate shielding the open ends of the tubes, an 'air supply conduit discharging into the mixing chamber and against the baflle plate, means for directing air'from the mixing chamber to the surface of liquid fuel in the starting receptacle, said baflle plate and the bottom of the starting unit having tubular nozzle members piercing the same and supplying air from said conduit to the receptacle, said tubular nozzle members being provided with hoods.

JosnPH E. FARRELL. 

